Is Atopic Dermatitis Due to Environment or Genetics? With Matthew Zirwas, MD

The commonly understood view of atopic dermatitis as a predominantly genetic disease may no longer represent the full picture, according to Matthew Zirwas, MD, who spoke in an interview about the increasingly important role environmental exposures are playing in disease development.

He spoke about this topic in his presentation, ‘Atopic Dermatitis, Barrier Breakdown: Understanding and Treating Atopic Dermatitis From the Inside Out,’ at the 2026 SDPA Summer Dermatology Conference, and was asked about the topic by the HCPLive editorial team following his session.^1,2 Zirwas explained his view suggesting genetic predisposition, though it remains relevant, may not play as strong of a role as environmental factors. Such factors may account for many of the trends seen in atopic dermatitis over the past several decades.

How Have Environmental Exposures Led to Increasing Rates of Atopic Dermatitis?

“In particular, we know that we now have answers for why it started to get more common in the 1970s,” Zirwas explained. “Why it's more common in the city than in the country [and] why it's more common in industrialized nations than in unindustrialized nations.”

Several common environmental exposures, including chemicals linked with catalytic converters, as well as materials found in polyester and nylon clothing and polyurethane foam cushions, may be major contributors to skin barrier dysfunction and the development of eczema, Zirwas stated. He noted such exposures became more and more common within the same period in which atopic dermatitis prevalence began rising, leading some to view environmental factors as bigger drivers of the skin disease in many patients who have traditionally been overlooked.

What Does Environmentally Driven Eczema Look Like?

He also emphasized that environmentally driven atopic dermatitis often presents differently than the classic form clinicians have historically linked with the condition. While genetically driven atopic dermatitis is typically characterized by onset during childhood, flexural involvement, and accompanying atopic conditions, the environmentally associated form more commonly takes place in adulthood, favors extensor surfaces and the trunk, and frequently lacks other atopic comorbidities.

Despite such clinical differences, Zirwas suggested that both forms of atopic dermatitis respond similarly to currently available medications. Zirwas noted the greater challenge, in his view, is the lack of recognition of many patients with environmentally-driven disease as having atopic dermatitis at all.

Disclosures: Galderma Laboratories, L.P, Regeneron Healthcare Solutions, GENZYME CORPORATION, Arcutis Biotherapeutics, Lilly USA, Novartis Pharmaceuticals Corporation, Dermavant Sciences, LEO Pharma, Verrica Pharmaceuticals, Incyte Corporation, AbbVie, and Pfizer.

References

1. Zirwas M. Atopic Dermatitis, Barrier Breakdown: Understanding and Treating Atopic Dermatitis From the Inside Out. Session presented at SDPA Summer 2026; June 10–14.

2. Zirwas M, Rosen T. No Label No Trouble: A Panel Review of Off-Label Medication Use. Session presented at SDPA Summer 2026. Jun 10-14, 2026.